and represents the imaginary portion of the second-order Love number which measures the efficiency at which the satellite dissipates tidal energy into frictional heat. This imaginary portion is defined by interplay of the body's rheology and self-gravitation. It, therefore, is a function of the body's radius, density, and rheological parameters (the shear modulus, viscosity, and others – dependent upon the rheological model). The rheological parameters' values, in turn, depend upon the temperature and the concentration of partial melt in the body's interior. The tidally dissipated power in a nonsynchronised rotator is given by a more complex expression. See also Cryovolcano Tidal acceleration Tidal locking Tidal heating of Io Io Volcano Observer Planetary differentiation References Planetary science Tidal forces